<script setup>
// 图片列表
import {useMouseInElement} from "@vueuse/core";
// 图片列表
const imageProp = defineProps({
  imageList: {
    type: Array,
    default: () => []
  }
})

/*
const imageList = [
  "https://yanxuan-item.nosdn.127.net/d917c92e663c5ed0bb577c7ded73e4ec.png",
  "https://yanxuan-item.nosdn.127.net/e801b9572f0b0c02a52952b01adab967.jpg",
  "https://yanxuan-item.nosdn.127.net/b52c447ad472d51adbdde1a83f550ac2.jpg",
  "https://yanxuan-item.nosdn.127.net/f93243224dc37674dfca5874fe089c60.jpg",
  "https://yanxuan-item.nosdn.127.net/f881cfe7de9a576aaeea6ee0d1d24823.jpg"
]
*/

// 1.小图切换大图显示
const activeIndex = ref(0)
//do bug:切换套图activeIndex没有重置为0,会导致如果其他sku图片会有i对应的数字那么多，会报错
const enterHandler = (i) => {
    console.log("iiii", i) //i变化导致大图list大图变化
    activeIndex.value = i
}
const getActive = (i)=>{
  //bug 解决点
  if(i===0&&activeIndex.value+1>imageProp.imageList.length){
    activeIndex.value = i
    return true;
  }
  return i === activeIndex.value
}

//2、放大镜效果

//2.1 useVue函数确定鼠标位置以及是否在大图内
const target = ref(null)
const {elementX, elementY, isOutside} = useMouseInElement(target);
//2.2 判断阴影有效位置left 100-300,top 100-300
const left = ref(0)
const top = ref(0)
const positionX = ref(0)
const positionY = ref(0)
watch([elementX, elementY, isOutside], () => {
  if (isOutside.value) return
  //x
  if (elementX.value > 100 && elementX.value < 300) {
    left.value = elementX.value - 100
  }
  //y
  if (elementY.value > 100 && elementY.value < 300) {
    top.value = elementY.value - 100
  }
  //边界处理

  if (elementX.value > 300) left.value = 200
  if (elementX.value < 100) left.value = 0

  if (elementY.value > 300) top.value = 200
  if (elementY.value < 100) top.value = 0

  //放大图
  positionX.value = -left.value * 2
  positionY.value = -top.value * 2
})



</script>


<template>
<!--  {{ elementX }} {{ elementY }} {{ isOutside }}-->
  <div class="goods-image">
    <!-- 左侧大图-->
    <div class="middle" ref="target">
      <img :src="activeIndex+1>imageList.length?imageList[0]?.image:imageList[activeIndex]?.image" alt=""/>
      <!-- 蒙层小滑块 -->
      <div class="layer" :style="{ left: `${left}px`, top: `${top}px` }" v-show="!isOutside"></div>
    </div>
    <!-- 小图列表 -->
    <ul class="small">
      <li v-for="(item, i) in imageList"
          :key="i" @mouseenter="enterHandler(i)"
          :class="{active:getActive(i)}"
      >
        <img :src="item?.image" alt=""/>
      </li>
    </ul>
    <!-- 放大镜大图 -->
    <div class="large" :style="[
      {
        backgroundImage: `url(${imageList[activeIndex]?.image})`,
        backgroundPositionX: `${positionX}px`,
        backgroundPositionY: `${positionY}px`,
      },
    ]" v-show="!isOutside"></div>
  </div>
</template>
<style scoped lang="scss">
.goods-image {
  width: 480px;
  height: 400px;
  position: relative;
  display: flex;

  .middle {
    width: 400px;
    height: 400px;
    background: #f5f5f5;
  }

  .large {
    position: absolute;
    top: 0;
    left: 412px;
    width: 400px;
    height: 400px;
    z-index: 500;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    background-repeat: no-repeat;
    // 背景图:盒子的大小 = 2:1  将来控制背景图的移动来实现放大的效果查看 background-position
    background-size: 800px 800px;
    background-color: #f8f8f8;
  }

  .layer {
    width: 200px;
    height: 200px;
    background: rgba(0, 0, 0, 0.2);
    // 绝对定位 然后跟随咱们鼠标控制left和top属性就可以让滑块移动起来
    left: 0;
    top: 0;
    position: absolute;
  }

  .small {
    width: 80px;

    li {
      width: 68px;
      height: 68px;
      margin-left: 12px;
      margin-bottom: 15px;
      cursor: pointer;

      &:hover,
      &.active {
        border: 2px solid $xtxColor;
      }
    }
  }
}
</style>